“Motion picture,” as the term is used herein, includes any type of audio-visual content stored on a medium of expression. It can include movies, episodes of broadcast television programs, corporate events, or other audio-visual content. The production and sale of counterfeit copies of motion pictures is a serious problem of long standing in the motion picture industry. Counterfeit copies of new motion pictures sometimes are sold to the public even before the motion picture has been released by the motion picture studio. These counterfeit copies are hard to trace, and it is a difficult job to identify and bring the counterfeiters to justice.
A particularly crude but widespread type of counterfeiting is the use of a video camera to copy a motion picture film projected on a motion picture theater screen. The copy made by this technique then is converted to a distributable format (e.g., DVD, video tape or digital file), and the illegal copies are sold to the public and otherwise distributed.
Attempts have been made in the past to stem the tide of such counterfeits by embedding identifiable codes into the images of the motion pictures. Such approaches can be useful in tracing the sources of where counterfeits of motion pictures were originally captured by a video camera. In theory, when a counterfeiter makes a video copy of the film, the identifiable codes also will be copied. Then, after the counterfeit has been distributed, it can be viewed by content owners, industry associations (e.g., MPAA), law enforcement personnel and other interested parties to determine which print of the film was copied. When that print number is traced to the theater or other location in which it was shown (sometimes at a preview prior to the formal release of the film) the counterfeiter can be identified as someone who had access to the screening.
One drawback associated with solely relying upon identifiable codes embedded into the video portion of the motion picture is that counterfeiting operations often combine video recordings taken from one location with audio recordings taken from another location in order to produce the final counterfeit copies that are distributed. Video and audio recordings of the same motion picture can be taken from a variety of different locations, where the particular video and audio recordings with the least number of defects or disturbances can be matched together to produce a counterfeit copy that most closely resembles the motion picture being copied. Further, when counterfeit copies are distributed in different languages in different countries, audio recordings from one language can be combined with a video recording from another location to produce a counterfeit copy in a different language. Once a counterfeiter obtains a clean copy of the video recording, this single video recording can be combined with respective audio recordings from other countries to produce counterfeit copies in various different languages. Thus, relying on counterfeit tracking mechanisms that focus solely on the video portion of the motion picture may not reveal information about where the audio portion of the counterfeit copy may have been pirated.
There have been attempts at audio watermarking motion pictures by inserting a particular artifact into a soundtrack of a copy of the motion picture at a particular location, where the location of such artifact in the soundtrack was specific to a particular copy of the motion picture. These prior techniques required different locations for the artifacts to be inserted into each copy of a motion picture, thereby limiting the number of different copies that can be made to the number of different locations an artifact can be placed. This also requires knowledge of the locations of where each artifact appears in each and every copy of the motion picture in order to determine sources of origin. Further, artifacts may be more noticeable in certain locations of a motion picture than in other, locations, thereby creating non-uniformity in both the quality of the copies of the motion pictures that are distributed and the usefulness of the artifacts.